Writing instrument



Feb. 5, 1963 c. N. JOHNSON WRITING INSTRUMENT 4 Sheets-Sheet 1 FiledJuly 28, 1958 FIGJ FIG.|O

FIG] 4 s y, I 4M VVHU 9 I 7 f 7 4 3 5 l, an a z2 Jf/ n Feb. 5, 1963 c.N. JoHNsoN WRITING INSTRUMENT 4 Sheets-Sheet 2 Filed July 28, 1958 M, my#wm/4% #fray/M675,

Feb. 5, 1963 c. N. JoHNsoN WRITING INSTRUMENT Filed July 28, 1958 4Sheets-Sheet 3 Feb. 5, 1963 c. N. JoHNsoN WRITING INSTRUMENT 4Sheets-Sheet 4 Filed July 28, 1958 United States Patent 3,076,437WRITING INSTRUMENT Clifford N. Johnson, 7421 Pleaseway Drive, St. Louis20, Mo. Filed July 23, 1958, Ser. No. 751,412 3 Claims. (Cl. 12d- 22)This invention relates to a writing instrument wherein the writing unitis allowed to fall by gravity a limited predetermined distance beyondthe forward end or tip of said writing instrument when the projectingmechanism is actuated. In particular, this invention relates to amechanical pencil wherein the writing unit or lead is allowed to fall bygravity a limited predetermined distance, which can be adjusted asdesired, beyond the tip of the pencil when the Writing unit stop or leadstop is actuated.

This application has subject matter in common with my co-pendingapplication Ser. No. 587,094, tiled May 24, 1956, now Patent No.2,854,950.

The use of extra thin lead in mechanical pencils has become increasinglypopular. This lead is approximately 0.036 inch in diameter and isfrequently broken due to the over extension thereof from the forward tipof a pencil. It is estimated that over titty percent of such lead iswasted since it is broken off so frequently in use. Present mechanicalpencils feed the lead from the forward end of the pencil in manydifferent ways, such as by spiral means actuated by rotation, by buttonmeans which when pushed positively moves the lead forwardly step bystep, or by clutch means actuated by rotation or by a spring clutch asnormally found in mechanical drafting pencils. With all of the presentfeed arrangements, the amount of lead which extends beyond the forwardend of the pencil is not positively measured by means projectingexternally from the pencil, but is visually estimated or moved by meanswithinv the pencil itself. Either way, there is no assurance that thedesired amount of lead will extend forwardly from the end of the pencil.

One of the principal objects of the present invention is to positivelymeasure by externally projecting means the amount of lead which extendsexternally downwardly `from the forward end of a mechanical pencil, andto maintain that amount regardless of repeated actuation of the leadforwarding mechanism.

Another object of the present invention is to provide retractable stopmeans which is projected beyond the writing end of a Writing instrumentfor preventing the writing unit from falling by gravity beyond apredetermined distance from the tip of the instrument regardless I"ofhow many times the lead forwarding mechanism may be actuated. Anotherobject is to provide in a writing instrument means normally positionedwithin said instrument which can be projected externally thereof tolimit the distance which the writing unit is allowed to project from thetip of the writing instrument and to limit this in an adjustable manner.Another object is to provide actuating means which when operated doesnot positively act upon or move the writing unit but simply allows thewriting unit to move by gravity to its predetermined writing position.This eliminates the necessity of providing means for pushing the writingunit or lead to its new or projected position.

Another object is to provide a simple and economical commercialconstruction having a self-contained writing unit assembly and magazineassembly which can be easily assembled into the barrel.

Another object of the present invention is to provide a mechanicalpencil wherein lead is allowed to move by gravity to its writingposition upon actuation of the projecting mechanism. Another object -isto provide a mechanical pencil wherein an additional supply of leadsfrom the lead magazine will by virtue of being located one ICC above theother in the Ilead tube and resting upon one another cause the servicelead to drop to its new position quickly because of the additionalweight thereon when the projecting mechanism is actuated.

Another object is to provide a lead clutch or collet, part of which islocated outside of the pencil barrel or casing which will firmly gripthe service lead at only one point said point being located adjacent tothe writing tip. Another object is to provide lead adjusting means forvarying the amount which the externally projecting lead stop will allowthe writing uni-t to fall or project beyond the writing tip.

Another object of the present invention is to provide a magazine for arepeater-type pencil having guide means therein for automaticallyfeeding leadv within the maga*- zine to the central opening in apositive and guided manner utilizing the fact that a right-handed personnormally rotates the pencil counterclockwise in his hand when looking atthe eraser end when bringing a more pointed edge into contact with thepaper.

Another object is to provide a large capacity magazine wherein the leadsare maintained in a predetermined upright position and are guided andproperly oriented with respect to the central opening. j

These and other objects and advantages will become apparent hereinafter.

The invention also consists in the parts and in the arrangements andcombination of parts hereinafter described and claimed. In theaccompanying drawings which form part of this specification and whereinlike numerals and letters refer to like parts wherever they occur:

FIG.1 is an enlarged longitudinal cross-sectional view of a writinginstrument embodying the present invention showing the lead or writingunit in its writing position after it has been worn to some extent, thedotted lines lshowing the extended position of the lead stop,

FIG. 2 is an end view of the writing tip of the instrument shown in FIG.1,

FIG. 3 is a greatly enlarged fragmentary longitudinal cross-sectionalview of the writing end of the instrument,

FIG. 4 is an enlarged fragmentary partial section of the writing end ofthe instrument with the lead stop in its projected position,

FIG. 5 is a view similar to FIG. 4 but with the -jaws of the clutch intheir forward and open position,

FIG. 6 is a greatly enlarged elevational viewof the unitary writingassembly,

FIG. 7 is a cross-sectional view taken along the line 7.-7 of FIG. 6,

FIGS. 8 and 9 are detailed views of the shoulder bearing and the leadselector with an integral extruded guide tube, respectively,

FIG. l0 shows the upper end of the magazine before the friction tube isapplied,

FIG. 11 is a sectional view along a slot showing the friction tubeassembled with said magazine,

FIG. l2 is a view of the instrument with the cap removed and in erasingposition,

FIGS. 13 and 14 are fragmentary sectional views of a modied eraserholding means wherein the eraser has a vthreaded cap which is threadedinto the magazine,

lFIGS. l5 and 16 are end views similar to FIG. 2 showl ing a pair ofmodified clutch jaws having a square central opening which automaticallycompensates for variances inthe size of the lead, as shown in FIGS. l5and 16,

FIG. 17 is a fragmentary longitudinal cross-sectional view showing mymodified magazine with guide means therein,

FIG. 18 is a cross-sectional view taken along the line 18-18 of FIG. 17,and

FIG. 19 is a fragmentary longitudinal cross-sectional view of the modiedmagazine without the guide means and showing one position which anunguided piece of lead might assume.

Referring now to the drawings in detail, it willbe seen that theembodiment of the invention which has been illustrated comprises awriting instrument 1 having a casing 2 with a projecting mechanism 3 andclutch 4 therein. The casing 2 comprises a barrel 5 and a cap 6 thereonwith a unitary writing unit assembly 7 and a magazine 8 therein.

The Cylindrical barrel has internal threads 9 at its forward end forreceiving the writing unit assembly 7. The upper portion of the barrel 5is provided with a plug 10 which slidably receives the magazine 8, saidplug 10 being slightly larger in diameter than the barrel 5 to provide abearing surface 11 for the inside of the push cap 6 having a pocket clip12 thereon. The barrel 5 is basically tubular and preferably cylindricalfor ease in manufacturing and printing names or advertisements thereon.

The writing unit assembly 7, best shown in FIGS. 5 and 6, comprises aclutch closing tube 13, a clutch 4 with a Vforward tip 14, a leadselector 15 and various other parts. lThe clutch closing tube 13 hasthreads 16 thereon, a tapered outer surfacey 17, a rear abutment 18, anda forward portion 19. The clutch 4 has an axial opening 2t)therethrough. The clutch closing tube has an opening therethrough and arear support 21` and a forward surface 22. The clutch 4 slidably setswithin the clutch tube -13 and is provided with a plurality of jaws 23having teeth 24 at their forward end for gripping the writing unit orlead 25. The outer inclined surfaces 26 of the jaws 23 slide withrespect to the surface 22. One of said jaws `23 is provided -with a slot27 having a bottom 28. The rear portion of said clutch 4 is providedwith internal threads 29 for receiving the forward end of the leadVselector 15, which is provided with an enlarged head or rear portion 30with an opening 31 therethrough and a surrounding concave or conicalsurface 32.

A clutch closing spring 33 is mountedv between the rear A'surface 1:8 ofthe clutch closing tube 13 and a rotatable clutch adjusting nut 34 fornormally biasing said clutch 4 and nut 34 upwardly. A vsleeve bearing 35having a shoulder 3.6 thereon is slidably mounted on Said lead selector15 which is .circumscribed by a lead stop spring Y37-positioned betweenupper surface of said clutch -adjust- 'fing 'nut 34 and the lowerisurface of said shoulder 36 for normally `biasing said members apart. Athin walled lead guide tube 38 is mounted within the clutch 4 and leadvfst-.lector 15 'for preventing lead from adhering to the teeth 24 ofthe jaws 23. If desired, the tube 38 may be formed integral with thelead iselector 15 as vshown in FIG. 9.

A lead stop 39 is provided in the longitudinal -slot 27 in the A-clutch4 Aand extends rearwardly and terminates in a bent portion 40 whichabuts against `the'sleeve bear- 'ing 135. The-lead stop 39 has a tip-41which is 'bent an- `gularlyinwardly toward the geometric axis -42 of thewriting instrument and has a sliding edge .43 thereon which s'lides onthe bottom 28 of the slot'27 in the clutch 4. The angle between the tip41 andthe geometric axis 42 is preferably-45 or less. 'Thelead stop 39is made from thin resilient metal and -the tip is adapted to spring'automatically into alignment with the lead 25 to prevent .the same fromfalling out of the opening and to position the amount to which itextends.

'The'magazine'assembly 8 comprises an outer magazine 44 andfan,adjustable magazine insert 45 vhaving an enlarged or inwardlyextending wall portion 446 to reduce the internal 'diameter Aand moreproperly support the lead therein. The enlarged wall portion 46 has aforwaidshoulder 47 adapted to vabutvagainst the top 32 of the.leadYselector ,15. -The magazine insert 45 also has aforward'edge-ISincontactingrelation with the sleeve type slide bearing 35, and externalthreads 49 whichre- ;ceive.internal threadsS on .an outerlead magazine44.

The outer magazine 44 is provided with prongs 51 which abut against alower surface 52 on the plug 10 and an indenta-tion 53 forming an eraserreceiving chamber 54 at the upper end thereof. An edge 55 is turned overat one point on a helical angle to cut a thread into an eraser 56 as itis initially screwed into the chamber 54. A tube 57 having slots 5Stherein frictionally fits over the upper end of the magazine 8 and isprovided with an outer bearing surface 59 to properly position the cap 6on the barrel 5. y

It is believed that the operation of the writing instrument 1 is obviousfrom the foregoing description. Referring to FIG. l, wherein all partsare shown in their assembled relation, if it is desired to project apiece of lead 25 or change the adjustment of worn projected lead, thecap 6 is pushed downwardly with respect to the barrel 5. In so doing,the cap 6, by reason of its tapered inner surface 60 cooperating withthe bearing surface 59 of the tube 57 forces the outer magazine 44 andmagazine insert 45 downwardly thereby moving the sleeve bearing 35downwardly causing the spring 37 to cornpress and the lead stop 39 tomove forwardly to the position shown in FIG. 4. In this position, theshoulder 47 is contacting the lead selector 15. Continued downwardpressure on the cap 6 moves the lead selector 15 Iand clutch 4 with theclutch adjusting nut 34 downwardly against the force of the clutchspring 33 thereby moving the clutch jaws 23 downwardly into openposition as shown in FIG. 5 so that lead 2 5 may freely fall through theenlarged central opening 20 until it is stopped by` the lead stop 39 inthe desired extended position.

The pressure on the cap 6 is then released which first causes the clutchjaws 23 to move upwardly and inwardly by reason of the clutch spring 33to close the ,opening so that the jaw teeth 24 bite into the properlyextended lead 25 at the writing tip 14 of the instrument. Thus, the leadis fixed with respect to the clutch 4. Con- ,tinued release of thepressure on the cap 6 causes the spring 37 to force the projectingmechanism and the cap r6 upwardly and movethe lead stop 39 upwardly toits retracted position as shown in FIG. l. At the Asame time and due tothe same force the magazine 8 and the magazine insert 45 move upwardlyand the shoulder'47 moves out of contact with the lead selector 15.

Referring to FIG. l, it is seen that the radial pressure on the clutchjaws 23 can be varied by rotating the clutch adjusting nut 34 toincrease or decrease the pressure on the clutch spring 33. Moving thenut 34 toward the `clutch closing tube 13 compresses the spring 33 andmov- `ing the nut 34 upwardly releases the spring 33.

To adjust or vary the distance which the lead stop 39 lextends beyondthe tip 14, the outer magazine 44 is rotated in relation to the magazineinsert 45 thereby moving the magazine insert 45 upwardly .or downwardlyto change the position of sleeve bearing 35 with respect to the writingtip. However, this does not change the distance D between the shoulder47 'and the top of the lead selector. The bearing 35 is initiallypositioned out ,of contact-with the enlarged head 30.of the leadselector 15 to allow adjustment in either direction. If the magazineinsert 45 is screwed into the outer magazine 44, the lead stop 39 movesupwardly or to a more rearwardly positionandcannot be extended as farfrom the writing tip l14.

The barrel 5 is short, as best seen in FIG. 12, so that in erasing theoperator is able to grasp the magazine itself and not the barrel. Thisgives a positive erasing action and does not allow the magazine to bobup and down when erasing, as might be the case when the barrel isgrasped. The bobbing is due-to the fact that the force of erasing mightovercome the force of the spring 37 so as to cause the barrel andmagazine to move relative to one another.

FIGS. 13 and 14 show -a lmodified eraser holder 61 in which the upperportion of the youter magazine 44 is provided with internal threads 62which are adapted to receive the threaded holder 61 of an eraser 64. Anannular groove 53 is also provided to form a stop means for the eraserholder 61 as in the form shown in FIG. 13. FIG. 14 shows the eraser 64and holder 61 in their extended position such as when the eraser ispartially worn.

FIGS. 15 and 16 are end views of a pair of modified clutch jaws 64having a substantially square opening 65 formed by reason of each jaw 64having a V-notch 66 therein whose sides are perpendicular to each other.FIG. 15 shows the jaws 64 open for receiving a relatively thick piece oflead 67, whereas FIG. 16 shows these same jaws 64 closer together forgrasping a relatively thin piece of lead 68. In this arrangement, onlytwo jaws are provided.

FIGS. 17 and 18 show a modified magazine 8a having guide means 69therein which contain a large number of individual pieces of lead in asubstantially upright position. Mechanical pencils of the repeater type(that is, where one lead after another is automatically fed from themagazine to the writing opening upon actuation of a button or cap at theupper end of the pencil) have in the past had an inherent disadvantage:in order for the lead to drop through the relatively small central hole31 in the lead selector 15, the lead must stand substantially upright.This requires the magazine to have a small diameter to prevent the lead,especially small or broken pieces, from assuming steep angles as shownin FIG. 19.

Because of this, magazines of present repeater type pencils have a smallinside diameter of between about 1A; inch to Li/32 inch if 0.036 inchdiameter lead is used and about 5&2 to 716 inch inside diameter if 0.046inch diameter lead is used. Because of this, it was recommended toinsert only about six to eight pieces of lead into the magazine so thatthey would not be too tightly compacted and would be free to fallthrough the relatively small central opening. However, when few pieceswere positioned in a magazine as recommended, the lead was free toassume the position shown in FIG. 19.

In my present construction, the magazine 8 may be provided with anenlarged wall section 46 to properly position the lead, or as shown inFIGS. 17 and 18, may be provided with what might be termed a spiralguide member 70 lixedly or loosely positioned in the magazine 8a. Thisproperly positions the lead and increases the capacity so that severaldozen pieces of lead, even as many as forty or more, may be placed inthe magazine 8a and fed in a guided manner to the small central opening31 in the lead selector 15.

As shown by the arrow L in FIG. 18, the lead moves spirally inwardlyuntil it reaches the center opening 31. The counter-clockwise arrow Tshown on the outside of the magazine 3a in FIG. 18 represents the normaldirection of twist or rotation by a righthanded person when bringing asharper point to bear on the paper. It has been found that persons whowrite with their right hand usually rotate a pencil counter-clockwisewhen changing the position of the lead. This normal tendency determinesthe direction of the spiral guide means 70 and automatically causes thelead to move from the outer chamber 71 to the intermediate chamber 72 tothe inner chamber 73 from which it enters the opening 31. Anotherinuence which causes the lead to automatically move spirally inwardly isthe conical surface 32 on the lead selector 15 which forms the bottom ofthe magazine. This surface 32 is higher at the outside than at thecentral portion so that the leads move downwardly by gravity as theymove inwardly.

Projections 74 are struck from the wall of the magazine to act in thesame manner as the forward shoulder 47 of the enlarged wall section 46to move the lead selector 15 when actuating the mechanism. Theprojections 74 are better seen in FIG. 19 wherein the spiral guide means7 0 has been omitted for clarity and to show improper positions whichpieces of lead may otherwise assume if guide means are not provided.

This invention is intended to cover all changes and modifications of theexamples of the invention herein chosen for purposes of the disclosure,which do not constitute departures from the spirit and scope of theinvention.

What I claim is:

1. In a writing instrument, a unitary self-contained writing assemblycomprising a lead selector and a clutch connected thereto at all times,said assembly having an opening therethrough for receiving lead, saidclutch having jaws thereon with outer inclined surfaces, a clutchclosing tube circumscribing said said clutch jaws at said inclinedsurfaces, a member connected to the upper portion of said clutch, aclutch closing spring positioned between said member and said clutchclosing tube for biasing the Y latter against said inclined surfaces,said lead selector having a head thereon, a bearing slidably mounted onsaid lead selector beneath said head, a lead stop extendinglongitudinally over a major portion of said writing assembly, said leadstop having an upper end portion terminating at said bearing and a lowerend portion positioned in a slot in one of said jaws, a lead stop springpositioned between said member and the head for biasing the upper end ofthe lead stop upwardly, said springs contacting opposite sides of saidmember, said lower end portion being adapted to extend downwardly inspaced axial alignment beyond the bottom of said opening in said clutchthereby compressing said lead stop spring.

2. In a writing instrument, a unitary self-contained writing assemblycomprising a lead selector and a clutch connected thereto at all times,said assembly having an opening extending therethrough for receivinglead, said clutch having jaws thereon with outer inclined surfaces, aclutch closing tube circumscribing said clutch jaws at said inclinedsurfaces, a member connected to the upper portion of said clutch, aclutch closing spring positioned between said member and said clutchclosing tube for biasing the latter against said inclined surfaces, saidlead selector having a head in the upper portion thereof, a bearingslidably mounted on said lead selector beneath said head, a lead stopextending longitudinally over a major portion of said writing assembly,said lead stop having a bent upper end portion contacting said bearingand a lower end portion positioned in a slot in one of said jaws, a leadstop spring positioned between said member and the bent upper endportion for normally biasing the lead stop upwardly, said springscontacting opposite sides of said member, said lower end portion beingadapted to extend downwardly in spaced axial alignment beyond the bottomof said opening in said clutch.

3. In a writing instrument, a self-contained writing assembly comprisinga lead selector and a clutch connected therebelow, said lead selectorand said clutch having an opening extending entirely therethrough, saidclutch having jaws therein with outer inclined surfaces, a clutchclosing tube circumscribing said clutch jaws at said inclined surfaces,clutch adjustment means mounted on said clutch, a clutch closing springpositioned between said clutch adjustment means and said clutch closingtube for biasing the latter against said inclined surfaces to move saidjaws inwardly and close said opening, said lead selector having a headthereon, a bearing slidably mounted on said lead selector beneath saidhead, a lead stop spring positioned between said clutch adjustment meansand said bearing for biasing said bearing toward said head, a lead stopextending longitudinally over a major portion of said writing assembly,said lead stop positioned within a slot in one of said clutch jaws andhaving an end portion contacting said bearing and being biased upwardlyby said lead stop spring, said lead stop having a lower tip normallypositioned within the slot in said jaws and adapted to extend downwardlytherebeyond in spaced axial align- 1,908,386 ment with .the Opening ,insaid lutch means. 2,726,637 2,854,950 References Cited in the file o fthis patent UNITED sTAjrEs PATENTS 6 321,785 Bewan; J1 11y 7,18858171697 1,779,54 man V.; 1- 00118, 1930 174,949

Wahl I May 9, 1933 Miller Dec. 13, 1955 Johnson" T.- Oct. 7, 1958FOREIGN PATENTS Germany Aug. 30, 1951 Great Britain Apr. 26, 1923

1. IN A WRITING INSTRUMENT, A UNITARY SELF-CONTAINED WRITING ASSEMBLYCOMPRISING A LEAD SELECTOR AND A CLUTCH CONNECTED THERETO AT ALL TIMES,SAID ASSEMBLY HAVING AN OPENING THERETHROUGH FOR RECEIVING LEAD, SAIDCLUTCH HAVING JAWS THEREON WITH OUTER INCLINED SURFACES, A CLUTCHCLOSING TUBE CIRCUMSCRIBING SAID SAID CLUTCH JAWS AT SAID INCLINEDSURFACES, A MEMBER CONNECTED TO THE UPPER PORTION OF SAID CLUTCH, ACLUTCH CLOSING SPRING POSITIONED BETWEEN SAID MEMBER AND SAID CLUTCHCLOSING TUBE FOR BIASING THE LATTER AGAINST SAID INCLINED SURFACES, SAIDLEAD SELECTOR HAVING A HEAD THEREON, A BEARING SLIDABLY MOUNTED ON SAIDLEAD SELECTOR BENEATH SAID HEAD, A LEAD STOP EXTENDING LONGITUDINALLYOVER A MAJOR PORTION OF SAID WRITING ASSEMBLY, SAID LEAD STOP HAVING ANUPPER END PORTION TERMINATING AT SAID BEARING AND A LOWER END PORTIONPOSITIONED IN A SLOT IN ONE OF SAID JAWS, A LEAD STOP SPRING POSITIONEDBETWEEN SAID MEMBER AND THE HEAD FOR BIASING THE UPPER END OF THE LEADSTOP UPWARDLY, SAID SPRINGS CONTACTING OPPOSITE SIDES OF SAID MEMBER,SAID LOWER END PORTION BEING